When I was a kid, my dad had some random rules on swearing. Usually it was okay, although he tell us "watch your fuckin' language". Occasionally, we'd get in trouble.

My sister and I were full-fledged garbage mouths by the age of ten and eight. Other moms would get kinda nervous whenever we came over to play, or if there were a bunch o' moms at like a birthday party or something. Mom never could keep a lid on that trash can of a mouth.